Abstract: A zoom lens system includes at least six lens groups, each of which has power. An interval between each pair of lens groups that are adjacent to each other among the at least six lens groups changes while the zoom lens system is zooming. Each of three lens groups, which are respectively located closest, second closest, and third closest to an image plane, out of the at least six lens groups consists of one or more bonded lenses.

Abstract: A zoom lens system includes: a first lens group having positive power; a second lens group having negative power; and following lens groups. The following lens groups include: a first focus lens group having negative power; and a second focus lens group having positive power, arranged adjacent to, and closer to the image than, the first focus lens group. The first and second focus lens groups move along an optical axis during focusing from an infinity focus point on a close focus point. During zooming from a wide-angle end toward a telephoto end, intervals between lens groups change with the first lens group fixed with respect to an image plane. The zoom lens system satisfies the Inequality ?0.23<f2/TTL<?0.15, where TTL is an optical total length at the telephoto end and f2 is a focal length of the second lens group.

Abstract: A zoom lens system includes at least six lens groups, each of which has power. An interval between each pair of lens groups that are adjacent to each other among the at least six lens groups changes while the zoom lens system is zooming. Each of three lens groups, which are respectively located closest, second closest, and third closest to an image plane, out of the at least six lens groups consists of one or more bonded lenses.

Abstract: A zoom lens system includes: a first lens group having positive power; a second lens group having negative power; and following lens groups. The following lens groups include: a first focus lens group having negative power; and a second focus lens group having positive power, arranged adjacent to, and closer to the image than, the first focus lens group. The first and second focus lens groups move along an optical axis during focusing from an infinity focus point on a close focus point. During zooming from a wide-angle end toward a telephoto end, intervals between lens groups change with the first lens group fixed with respect to an image plane. The zoom lens system satisfies the Inequality ?0.23<f2/TTL<?0.15, where TTL is an optical total length at the telephoto end and f2 is a focal length of the second lens group.

Abstract: A zoom lens system comprises, in order from an object side to an image side: a first lens group having a positive power; a second lens group having a negative power; an aperture stop, a third lens group having a positive power; and a fourth lens group having a negative power. During zooming, a total length of the zoom lens system does not change, while a distance between each adjacent two of the lens groups changes, and the aperture stop moves along an optical axis independently of the second lens group and the third lens group. The zoom lens system satisfies condition (1) 6.0<f1/fw<20.0 and condition (2) 0.5<|f4|/fw<4.0, where f1 is a focal length of the first lens group, f4 is a focal length of the fourth lens group, and fw is a focal length of the zoom lens system at a wide-angle limit.

Abstract: A zoom lens system comprises, in order from an object side to an image side: a first lens group having a positive power; a second lens group having a negative power; an aperture stop, a third lens group having a positive power; and a fourth lens group having a negative power. During zooming, a total length of the zoom lens system does not change, while a distance between each adjacent two of the lens groups changes, and the aperture stop moves along an optical axis independently of the second lens group and the third lens group. The zoom lens system satisfies condition (1) 6.0<f1/fw<20.0 and condition (2) 0.5<|f4|/fw<4.0, where f1 is a focal length of the first lens group, f4 is a focal length of the fourth lens group, and fw is a focal length of the zoom lens system at a wide-angle limit.

Abstract: A zoom lens system comprising a plurality of lens units each being composed of at least one lens element, and comprising, in order from an object side to an image side, a first lens unit having positive optical power, a second lens unit having negative optical power, a third lens unit having positive optical power, a fourth lens unit having positive optical power, and a fifth lens unit having negative optical power, wherein the first lens unit is composed of two or less lens elements, the third lens unit is composed of five or more lens elements, and the condition: 5.0<f1/f3<8.0 (f1: a focal length of the first lens unit, f3: a focal length of the third lens unit) is satisfied.

Abstract: A zoom lens system comprising: a positive first lens unit; a negative second lens unit; a positive third lens unit; a fourth lens unit; and at least one subsequent lens unit, wherein the subsequent lens unit(s) includes a negative lens unit, the first and third lens units are respectively composed of two or less lens elements and four or more lens elements, the first and second lens units move along an optical axis in zooming, and the conditions: 0.0<LGmax/LG2<1.5, 0.2<|f2/fW|, and 0.1<|fe/f2| (LGmax: a maximum value of an axial thickness of the subsequent lens unit(s), LG2: an axial thickness of the second lens unit, fW, f2, and fe: focal lengths of the entire system at a wide-angle limit, the second lens unit, and a negative lens unit located closest to the image side) are satisfied.

Abstract: A zoom lens system, in order from an object side to an image side, comprising: a first lens unit having positive optical power; a second lens unit having negative optical power; a third lens unit having positive optical power; a fourth lens unit; and at least one subsequent lens unit, wherein the subsequent lens unit(s) includes a lens unit having negative optical power, the first lens unit is composed of two or less lens elements, the third lens unit is composed of four or more lens elements, the first lens unit and the second lens unit move along an optical axis in zooming, and the condition: 0<|fW/fe<2 (fe: a focal length of a lens unit having negative optical power and located closest to the image side in the entire system, fW: a focal length of the entire system at a wide-angle limit) is satisfied.

Abstract: A single focal length imaging optical system, in order from an object side to an image side, comprising: a front unit composed of a plurality of lens elements; an aperture diaphragm; and a rear unit composed of a plurality of lens elements, wherein the front unit, in order from the object side to the image side, includes a lens element having negative optical power, a lens element having negative optical power, and a lens element having positive optical power, and includes a lens element having positive optical power and placed closest to the image side, and the rear unit includes a focusing lens unit which is composed of at least one lens element and moves along an optical axis in focusing from an infinity in-focus condition to a close-object in-focus condition, and a lens element having negative optical power and placed closest to the image side.

Abstract: A zoom lens system comprising a plurality of lens units each being composed of at least one lens element, and comprising, in order from an object side to an image side, a first lens unit having positive optical power, a second lens unit having negative optical power, a third lens unit having positive optical power, a fourth lens unit having positive optical power, and a fifth lens unit having negative optical power, wherein the first lens unit is composed of two or less lens elements, the third lens unit is composed of five or more lens elements, and the condition: 5.0<f1/f3<8.0 (f1: a focal length of the first lens unit, f3: a focal length of the third lens unit) is satisfied.

Abstract: A zoom lens system comprising: a positive first lens unit; a negative second lens unit; a positive third lens unit; a fourth lens unit; and at least one subsequent lens unit, wherein the subsequent lens unit(s) includes a negative lens unit, the first and third lens units are respectively composed of two or less lens elements and four or more lens elements, the first and second lens units move along an optical axis in zooming, and the conditions: 0.0<LGmax/LG2<1.5, 0.2<|f2/fW|, and 0.1<|fe/f2| (LGmax: a maximum value of an axial thickness of the subsequent lens unit(s), LG2: an axial thickness of the second lens unit, fW, f2, and fe: focal lengths of the entire system at a wide-angle limit, the second lens unit, and a negative lens unit located closest to the image side) are satisfied.

Abstract: A zoom lens system, in order from an object side to an image side, comprising: a first lens unit having positive optical power; a second lens unit having negative optical power; a third lens unit having positive optical power; a fourth lens unit; and at least one subsequent lens unit, wherein the subsequent lens unit(s) includes a lens unit having negative optical power, the first lens unit is composed of two or less lens elements, the third lens unit is composed of four or more lens elements, the first lens unit and the second lens unit move along an optical axis in zooming, and the condition: 0<|fW/fe<2 (fe: a focal length of a lens unit having negative optical power and located closest to the image side in the entire system, fW: a focal length of the entire system at a wide-angle limit) is satisfied.

Abstract: A zoom lens system comprising: a front unit having negative optical power as a whole and including a first lens unit located closest to the object side; and a rear unit having positive optical power as a whole, wherein at least the front unit moves along an optical axis in zooming, the first lens unit is composed of at most three lens elements, the rear unit includes a lens unit having an aperture diaphragm between lens elements, an air space between which is not varied in zooming, a sub lens unit comprising a part of a lens unit constituting the rear unit moves in a direction perpendicular to the optical axis, and the condition: 0.1<BF/fW<2.0 (?W>72°, FNOW<2.9, BF is a back focal length of the entire system at a wide-angle limit, fW is a focal length of the entire system at a wide-angle limit, ?W is a view angle at a wide-angle limit, FNOW is an F-number at a wide-angle limit) is satisfied; an imaging device; and a camera are provided.

Abstract: A zoom lens system, in order from an object side to an image side, comprising a first lens unit having negative optical power, a second lens unit having positive optical power, and at least one subsequent lens unit having optical power, wherein in zooming from a wide-angle limit to a telephoto limit, the lens units are moved along an optical axis such that an air space between at least any two lens units among the lens units should vary, so that variable magnification is achieved, wherein the first lens unit includes a lens element having a reflecting surface for bending a light beam incident from the object, and wherein the condition is satisfied: 0.20<|fG1|/fT<0.52 (fT/fW?4.0, fG1 is a composite focal length of the first lens unit, and each of fT and fW is a focal length of the entire system at a telephoto limit or a wide-angle limit), an imaging device and a camera are provided.

Abstract: A zoom lens system comprising: a front unit having negative optical power as a whole and including a first lens unit located closest to the object side; and a rear unit having positive optical power as a whole, wherein at least the front unit moves along an optical axis in zooming, the first lens unit is composed of at most three lens elements, the rear unit includes a lens unit having an aperture diaphragm between lens elements, an air space between which is not varied in zooming, a sub lens unit comprising a part of a lens unit constituting the rear unit moves in a direction perpendicular to the optical axis, and the condition: 0.1<BF/fW<2.0 (?W>72°, FNOW<2.9, BF is a back focal length of the entire system at a wide-angle limit, fW is a focal length of the entire system at a wide-angle limit, ?W is a view angle at a wide-angle limit, FNOW is an F-number at a wide-angle limit) is satisfied; an imaging device; and a camera are provided.

Abstract: A zoom lens system, in order from an object side to an image side, comprising a first lens unit having negative optical power, a second lens unit having positive optical power, and at least one subsequent lens unit having optical power, wherein in zooming from a wide-angle limit to a telephoto limit, the lens units are moved along an optical axis such that an air space between at least any two lens units among the lens units should vary, so that variable magnification is achieved, wherein the first lens unit includes a lens element having a reflecting surface for bending a light beam incident from the object, and wherein the condition is satisfied: 0.20<|fG1|/fT<0.52 (fT/fW?4.0, fG1 is a composite focal length of the first lens unit, and each of fT and fW is a focal length of the entire system at a telephoto limit or a wide-angle limit), an imaging device and a camera are provided.